the national central banks (NCBs) of the 28 Member States of the European Union (EU)

The Treaty establishing the European Community and the Statute of the European System of Central Banks and the European Central Bank (Statute of the ESCB) form the legal basis of the ESCB. The Treaty regulates the performance of central banking tasks in the euro area by the ECB and the national central banks (NCBs). The Statute specifies the relevant tasks and functions of the ECB and the NCBs.

The legal texts which establish the European System of Central Banks (ESCB) – the Treaty establishing the European Community and the Statute of the ESCB – were written on the assumption that all EU Member States will adopt the euro and that therefore the ESCB will conduct all the tasks involved in the single currency. However, until all EU countries have introduced the euro, it is the Eurosystem which is the key actor. The term "Eurosystem" therefore serves to facilitate understanding of the structure of central banking in the euro area.